Cage for needle bearings



Nov. 27, 1956 G. SCHAEFFLER ETAL 2,772,123

CAGE FOR NEEDLE BEARINGS 7 Filed June 11, 1954 4 Sheets-Sheet l FIG-fINVEN7'0P5 Nov. 27, 1956 G. SCHAEFFLER ETAL 2,772,123

CAGE FOR NEEDLE BEARINGS Filed June 11, 1954 4 Sheets-Sheet 2 INVENI'OQSejfl6 Nov. 27, 1956 G. SCHAEFFLER EIAL 2,772,128

CAGE FOR NEEDLE BEARINGS 4 Sheets-Sheet 5 Filed June 11, 1954 )NVENTOPSG ficlzaeffer Nov. 27, 1956 G. SCHAEFFLER EIAL CAGE FOR NEEDLE BEARINGS4 Sheets-Sheet 4 Filed June 11, 1954 INVENTORS G @cfpa efzez UnitedStates Patent CAGE FOR NEEDLE BEARINGS Georg Schaeffler and Emil Bensch,Herzogenaurach, near Nurnberg, Germany, assignors to IndustriewerkSchaeftier, Herzogenaurach, near Nurnberg, Germany Application June 11,1954, Serial No. 436,161 Claims priority, application Germany June 13,1953 2 Claims. (Cl. 308-217) Individual guiding of the roller membershas largely become the current practice in the construction of rollerbearing cages, but an exception is formed by the needle bearing wherein,because of the relatively high supporting capacity required, the solidneedle construction has been retained as far as possible. The number ofwebs is kept as low as possible in the means employed for guiding andretaining the needle so that groups of needles bear against one anotherand only the outer needles are directly guided in an axially parallelposition by the few webs. The modern method of individually guiding eachneedle in an aperture has shown, however, that the guiding means is alsoof great importance for the sup porting capacity, and it has beenrecognised that, between the two extremes of, on the one hand,constructing the cage with few webs just sufliceint for stability and,on the other hand, of constructing the cages with individual guiding ofthe needles and with webs equal to the number of needles, optimumsupporting capacity can be obtained if it is possible to increase thenumber of needles and to effect the guiding with the same action as isfound with individual guiding. This fact becomes more important inproportion as the diameter of the roller members becomes smaller.

Thus, on the one hand, the number of needles is of decisive importancein the bearings in question, while, on the other hand, it is impossibleto neglect exact axially parallel guiding of the needles. This conditionis fulfilled by the invention in that two needles are always arranged ina cage aperture in such manner that each needle is guided by theadjoining web surface which forms a plane surface or a surface adaptedto the surface of the needle. The arrangement in pairs reduces thenumber of webs, while the width of the web, which can be made smallcorresponding to manufacturing technique, can remain unaltered. Forexample, if a bearing with an inner race of 18 mm. diameter has 13needles of 2.5 mm. diameter, which are individually accommo' dated, 18needles can be fitted if individual guiding of pairs is employed, andthis represents an increase of 38%. The number of webs is reduced from13 to 9.

Another feature of the invention is the retention of the needles, withindividual guiding in pairs, in an aperture in the cage, and also theconstruction of the retaining means. In cages having apertures andindividually guided roller members, it is known to use retaining meansconsisting in projections of material from the webs into the apertures,the distances between which are less than the diameter of onevrollermember, for example of one roller or needle.

When two roller members are arranged in an aperture in the cage, thecurvatures of the generated surfaces which touch one another in thecentre of the apertures make it possible, upon the raising or loweringof the roller members in opposite radial directions, for the said tworoller members to take up less space in tangential width thancorresponds to the sum of their two diameters.

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Thus, a width of the web projections which would suflice in theindividual arrangement is no longer effective as a retaining means whenthe roller members are in varying radial positions, and the rollermembers may drop out seriatim.

According to another feature of the invention, the dropping of theneedles out of the cage alone or out of the cage in combination with theinner or outer race thereof is obviated in different ways having thecommon feature that projections are contrived on the web or on the endsurface of the recess, which projections limit the movement of oneneedlearound the other along the surface lines thereof.

Thus, the pairs of needles can be so retained that their movement aroundone another is so limited on the webs alone, that is to say on thesurface of the needles, that only the radial clearance necessary foroperation is permitted.

The web flanks are so fashioned as mainly to form part of a hollowcylinder around the needles, the diameter of which hollow cylinder isonly greater by the necessary clearance than the diameter of the needle.The result is therefore obtained that the surfaces of the boundary websproject into an imaginary cylinder mainly on those sides of the webclose to the bore of the cage or on those sides of the web which are onthe external diameter of the cage, which imaginary cylinder would bedescribed by the needles when altering their position relatively to thepitch cycle of the cage and when contacting one another by their innergenerated surfaces.

However, with needles having tapered ends, blocking webs can becontrived radially in the cage in the centre of the end faces of theapertures, and the said blocking members permit radial movement of eachindividual needle but limit tangential movement thereof. Thus, theprojections on one side of the inner and outer edges of the web for eachneedle alone sufi'ice for radial retention, the amount of tangentialmovement of each needle being less than the size of the tangentialprojection of the cage.

In the construction of these retaining means, in the manner hereinbeforedescribed, only on the surfaces or in the bore surface of the cage,there is obtained satisfactory retention of the needles, if desired,together with retention of the inner or outer race.

In cages for roller hearings or needle bearings, a number of possibleconstructions are known which can also be employed for retaining rollermembers disposed in pairs, and these constructions can be used for thepresent purpose if there is a simultaneous guiding of each needle on theadjoining web. The invention can be applied to the most diverse types ofcages such, for instance, as fiat cages, divided cages or multi-rowcages.

For a better understanding of the invention and to show how the same canbe carried into effect, reference will now be made to the drawings,wherein:

Figure 1 is a plan view of a cage aperture having the needles;

Figure 2 is an aperture as in Figure l but with blocking webs on the endparts of the cage apertures;

Figure 3 is a section on the line III-III of Figure 2;

Figure 4 is a section through a special construction of a cage;

Figure 5 is a section through a cage wherein the needles are retained byrings;

Figure 6 is a section through a cage wherein the needle are retained onthe outside by a race;

Figure 7 is a section through a cage wherein the needles are retained onthe inside by a race;

Figure 8 is an upper plan view of a cage part wherein the end faces ofthe needles are fiat;

Figure 9 is a section along the line IX1X of Figure 8;

Figure 10 is a section through a cage part in a special construction ofthe cage;

Figure 11 is a section along the line XIXI in Figure 10; Y Y

. Figure 12 is an upper plan view of a cage aperture in a specialconstructional form; and V Figure 13 is a section on the line XIIIXHI ofFigure 12.

Referring to Figure 1, thecage 1 has end faces 2 and 3 through which thewebs 4 are interconnected, with the result that the apertures 5 areformed, fitted in each of which are two needles 6 and 7. The figureshows that the needles are uided by the'edges 8 and 9 of the apertures 5and are prevented from lengthwise movement by the edges 10 and 11. t

The left-hand part of Figure 1 shows how, for retaining purposes, theneedles can be secured, for example, by luglike retaining projections 12such as are generally known in the roller bearing art.

Also apparent in Figure 2 are the retaining projections 12 which retainthe needles 6 and 7, but in addition webs 13 are provided which extendsubstantially over the entire.

wall thickness of'the cage,'as can be clearly seen in Figure 3. The webs13 prevent the needles from dropping out, and co-operate with theprojections 12, as can be seen clearly in Figure 3. This is clearlyapparent from the right hand side of Figure 3, where the two needles 6and 7 are illustrated in their extreme positions. The right-hand side ofFigure2 also shows that, instead of using the individual retainingprojections 12, it is also possible to contrive, on the edges 8 and 9,retaining surfaces Hand 15 which can be produced, for example, bydeformation. 7

Figure 4 shows one possible way in which the deformations might beproduced. In this case, projections 16 are contrived on the cageelements which'are produced, for example, by injection moulding, and theprojections .16

are deformed before or after the fitting of the needles 6 and 7 so as toassume the position illustrated on the righthand side of Figure 4.

Figure 5 shows how the said retaining projections can be replacedby'special retaining strips 17 and 18 known per se. It is of coursepossible to provide one of these rings on one side and materialdeformations or the like on the other side.

In Figure 6, the retaining projections on the outer periphery of thecage have been replaced by the race 19, and

in the construction according to Figure 7 the retaining projections onthe inner periphery of the cage have been replaced by the race 26.

Figures 8 and 9 illustrate another method of retaining the needles. Itis apparent, more particularly from Figure 9, that the cross-sections ofthe projections lie within an imaginary cylinder'21, the axis of whichis the line of contact between the two needles 6 and 7 and the radius ofwhich corresponds at least substantially to the diameter of one needleless the clearance for the needles in the apertures. The line of contactbetween the needles is designated by 24.. Parts of the retaining means12 in the constructional example illustrated must always lie inside theimaginary cylinder, the said parts being those which may have toaccommodate movements of adjacent needles as permitted by the existingclearance.

Figures 10 and 11 illustrate another constructional form wherein theneedles 6 and 7 are guided and retained by the cage 1 underneath theircentres. In this case, the race 19, which is disposed in a mannersimilar to that shown in Figure 6, has a flange 26.

On the righthand side of Figure lO the intermediate web 13 illustratedin Figure 6 has been omitted, but to compensate for this the projections12 are drawn in closer to the needles so that the condition as explainedwith reference to Figure 9 is fulfilled. I

in the construction according to Figures 12 and '13,

there are provided within the aperture 5 in the cage 1' projections 27and' 28 which, as shown in Figure 13, do

' not extend over the entire wall thickness'of the cage 1,

in contrast to the intermediate webs 13. The projections 27 and 28 areso disposed as to'project above and below V the pitch circle into thefree space between the needles, and it is advantageous for the innerprojection 28 tobe narrower than the outer projection 27. It is readilyapparent from the right-hand'side of Figure 13 that, when projectionssuch as 27 and 28 are used, additional retaining means in the cage 1such, for example, as the deforma-.

tions 12 and 14 in the earlier figures, can be omitted.

We claim:

l. A cylindrical bearing cage for needles comprising a pair of parallelend faces, a plurality of parallel webs interconnecting said end facesand thereby forming a plurality of spaced apertures, a pair of taperedended needles adjoiningly arranged in each of said apertures, protrudingsurfaces formed on said webs, and web-like projections formed centrallyon said end faces intermediate of said webs extending radially in saidapertures for coacting with said webs to effect individual guidance ofsaid adjoining needles and forcoacting with said protruding surfaces foreffecting retention of said adjoining needles Within said.

aperture.

2. A cylindrical bearing cage for needles comprising a pair of parallelspaced end faces,'a plurality of parallel spaced webs formedtransversely of said end faces for interconnectingthem andtherebyforming a plurality of spaced sockets, a pair of adjoining tapered endedneedles rotatably arranged in each of'said sockets, protruding edgesformed on the edges of said webs and extending within the space of saidsockets, andweb projections extending radially in the cage within thesockets and formed on said end faces for engaging said tapered ends ofsaid adjoining needles thereby to effect individual guidance of saidadjoining needles and to coact with said protruding edges for retainingsaid adjoining needles within said

